Corrosion found in Shippingport nuclear reactor containment building

By Bill Vidonic, Times Staff
Published: Friday, April 24, 2009 9:58 PM EDT
SHIPPINGPORT - An inspection Thursday revealed corrosion in the steel lining of the nuclear reactor containment building of Beaver Valley Nuclear Power Station's Unit 1, according to FirstEnergy Corp.

No radiation was released from the building, and there was "no impact to the public health or safety of any employees," FirstEnergy spokesman Todd Schneider said Friday evening.

The Unit 1 reactor had been shut down since Monday for scheduled refueling and maintenance. As part of that work, Schneider said, the containment building that surrounds the reactor underwent a standard inspection.

The containment building has concrete walls that are 4 feet thick, Schneider said, and there's a 3/8-inch-thick steel lining on top of that concrete in the building's interior.

The steel is coated with what Schneider described as "nuclear-grade paint." An inspection showed a blister in some of that coating. The blister wasn't cracked, Schneider said.

Once the coating was cleaned, Schneider added, workers found that the steel underneath it had corroded through to the concrete wall. The affected area of the steel is in the shape of a rectangle, Schneider said, about one inch long by about 3/8-inch high. That's just under the size of a standard paper clip.

Schneider said the concrete beneath the steel lining was not cracked or damaged by the steel corrosion, so there was no danger of a radiation leak.

As required by federal regulations, the Nuclear Regulatory Commission was notified about the blister, Schneider said, though the discovery was not considered an emergency.

Wes Hill, director of Beaver County Emergency Services, said Friday evening that his department was not notified of the discovery.

Schneider said the blisters have been discovered at other nuclear plants in the past, so there's an established procedure to follow in making repairs.

The corroded steel will be removed, Schneider said, and another piece of steel will be welded into place. The removed steel will be examined to try to determine what caused the damage.

The affected area was last inspected in 2007 during another maintenance outage, Schneider said, and no problems were found then, so the corrosion occurred within the last couple of years.

Schneider would not say how long the reactor will remain off line for its scheduled maintenance, but said Thursday's discovery wouldn't delay the reactor restart; the repair to the steel will proceed during the refueling and maintenance work.

Once repairs are made, Schneider said, tests will be conducted "to ensure the safe operation of the plant" before the reactor is restarted.

The reactor was first brought online in 1976.

The Shippingport nuclear power station's second reactor, Unit 2, remained online and operating normally Friday, Schneider said. That unit, first online in 1987, was last inspected in spring 2008, he added; no problems were detected in that building at that time.